1. Field of the Invention
The present invention relates generally to mass transfer devices. More particularly the invention concerns a unique permeability separatory apparatus adapted to effectively resolve the different components of multicomponent fluids.
2. Discussion of the Invention
A number of designs exist for mass transfer devices and separatory apparatuses using small hollow capillary fibers that function as semi-permeable membranes. The methods for making these devices are well known.
These mass transfer devices typically use a number of hollow capillary fibers enclosed in a rigid housing with appropriate inlet and outlet fittings. The fibers generally extend from end to end in this housing and are encapsulated at each end with a potting compound. Typically the central portions of the fibers are unsupported. The ends of the fibers are open to allow the flow of a liquid. Sealing means are provided by the potting compound allowing flow of one fluid, for example, blood, through the fibers while a second fluid, for example, dialysate, flows around the exterior of the fibers.
A common drawback of all prior art mass transfer devices known to applicant resides in the fact that all use large bundles of fibers without providing any type of means for precluding the channeling of the external (dialysate) fluid around the fiber bundle. Such channeling markedly reduces efficiency of the devices and renders them marginal for certain applications.
Exemplary of prior art mass transfer devices are the devices described in U.S. Pat. Nos. 3,228,876 and 3,228,877 issued to H. I. Mahon. These devices represent the most pertinent art known to applicant and serve to clearly illustrate the novel aspects of the devices of the present invention as described hereinafter. In the Mahon devices, the fiber bundle is housed within a cylindrical shaped housing with the ends of the bundle being supported within a suitable potting compound. More particularly, Mahon seeks to achieve the announced objects of his invention by providing a cell that incorporates a specific membrane element comprising a multiplicity of substantially unsupported, fine, continuously hollow fibers.
To ensure maximum efficiency, the devices of the present invention embody means to prevent dead spaces within the fiber bundles and to preclude channeling of the external fluid around the fiber bundles. In this way the total capabilities of the fiber membranes are brought to bear to maximize the fiber transport potential of the device. More particularly the deficiencies of the prior art devices are largely overcome in the devices of the present invention through the use of a multiplicity of fiber bundles which are effectively supported within non-cylindrical housings. The reduced cross-section of the individual fiber bundles in conjunction with the non-cylindrically shaped housings permit increased penetration of the dialysate or rinsing liquids thereby making the mass transfer substantially more efficient. To further guard against fluid channeling and to maximize uniform fluid flow along the external surfaces of the individual fibers which form the fiber bundles, uniquely configured fluid diverter elements are stratigically placed within the devices. These elements are configured to optimize the fluid flow characteristics of the units and to eliminate the highly undesirable fluid channeling exhibited by prior art units.